Eddy current acquisition systems typically comprise an acquisition instrument, a probe cable slip ring, a probe, a probe adapter, a probe pusher, a take up reel, a probe pusher power supply, a probe pusher controller and in the case of inspection techniques requiring rotating probe technologies, a probe motor controller. For different test missions compatible components must be assembled into an inspection system particular to the mission. A probe is selected for an inspection technique and may incorporate an eddy current bobbin, rotating coil technologies or array probe technologies. A probe adapter compatible with the probe, probe extension cable and the acquisition instrument is also collected. The probe coils, via wires running through the probe shaft, are connected to an acquisition instrument via the probe adapter probe extension cable and the probe cable slip ring. In the case of a rotating probe, probe motor control wires are also routed through the probe shaft and connected to a suitable probe motor controller. The probe pusher that urges the probe on its distal end through a target is connected to a compatible probe pusher controller and probe pusher power supply by controller and power supply cables specific to the hardware.
Routinely, a variety of each component is required to assemble required components for a given mission, and the assembled components need to be correctly configured, both through hardware and software, for each mission. Avoiding human error in assembling the components and correctly configuring them is time-consuming and imperfect, resulting in a costly loss of measurement time and data and a risk of damage to the components, but perhaps most costly is the human exposure to radiation required to assemble and configure these several components into an efficacious eddy current test system.
The objective of the present invention is to present components of an eddy current test system in a consolidated footprint and each with an identifier and each connected to a host computer that recognizes each element and confirms that the components are appropriate to a mission type. The computer also recognizes compatible and incompatible components for the mission and confirms compatibility to the user or directs the user to a change of components.
It is characteristic in eddy current measurement of remote tubular targets that the eddy current probe is pushed through the target by the probe pusher to a target measurement position previously located as a zone of interest for inspection in the target. The probe is advanced to the known position by tracking linear movement of the shaft through the probe pusher a predetermined distance. Typically, the shaft probe pusher includes an encoder that tracks probe shaft movement. However, there is mechanical error measuring distance as a length of shaft pushed through the probe pusher caused by shaft sag, pusher wheel slippage and also from substitution of different probe pushers, shafts, and take-up reels employed for different measurements. Therefore, it is another object to provide a measurement that repeatably and reliably locates a probe at a position within the target that is not dependent on the particular system components assembled.
To maintain the probe shaft taut between the probe pusher and the take-up reel it is usual to employ a mechanical clutch on the reel. Mechanical clutches are effective but present a maintenance and adjustment challenge. Because the pusher and reel are contaminated after use, repair or adjustment are usually done in a “hot shop” environment where radiation protection is required. Repair is cumbersome and expensive, so by eliminating known maintenance issues such as the mechanical clutch, associated operating costs can be reduced. It is therefore a further object to provide an electronic clutch that does not require the maintenance and adjustment of a mechanical clutch.